Chapter 8 Flashcards
Totality of an organism’s chemical reactions
Metabolism
Reactions that release energy and break down molecules
Catabolic
Reactions that consume energy and build up larger molecules
Anabolic
What type of reaction is photosynthesis? Cellular respiration?
Anabolic, catabolic
What reaction requires enzymes to catalyze reactions?
Anabolic
Energy that is exerted
Kinetic
Stored energy in a position
Potential
Occurs without an input of energy
Spontaneous
Portion of a system’s energy that can perform work when the temperature and pressure are uniform throughout the system.
Free energy
Net release of free energy
Exergonic
For an exergonic reaction, is ΔG positive or negative?
Negative
Absorbs free energy
Endergonic
What is the sign for free energy?
ΔG
What are the 3 main kinds of work a cell does?
Chemical, transport, mechanical
What makes up ATP?
Sugar ribose, adenine, phosphate groups
Use of an exergonic process to drive an endergonic one
Energy coupling
Energy required to contort the reactant molecules so the bonds can break
Activation energy
Serves as a catalyst in a reaction
Enzyme
Reactant on which an enzyme works
Substrate
Region of an enzyme that binds the substrate and forms the pocket where catalysis occurs
Active site
Change in shape of the active site of an enzyme so that it binds more snugly into the substrate
Induced fit
Explain how protein structure is involved in enzyme specificity
Must have the right shape of its active site and substrate
What are some factors that could affect the rate of enzyme action?
Initial concentration of substrate, pH, temperature
Inorganic helpers for catalytic activity
Cofactor
Organic helper for catalytic activity
Coenzyme
Reduces the activity of an enzyme by entering the active site in place of the substrate
Competitive inhibitor
Reduces the activity by binding to a location other than the active site, changing the shape so the active site doesn’t catalyze the conversion of substrate to product
Noncompetitive inhibitor
A protein’s function at one site is affected by the binding of a regulatory molecule to a separate site
Allosteric regulation
What’s the difference between an allosteric activator and inhibitor?
Activator stabilizes the active form while the inhibitor stabilizes the inactive form
Measurement of the amount of disorder in the molecules that make up the system
Entropy
States that a process will be spontaneous when it results in an increase of total entropy in the universe
Second law of thermodynamics
Total heat content of a system
Enthalpy
Energy cannot be created nor destroyed
1st law of thermodynamics
How does an enzyme act as a catalyst?
Lowers the activation energy of a chemical reaction
